1. Field of the Invention
The present invention relates to an image processing system and, more particularly, to image synthesis for obtaining a synthesized image by synthesizing two or more images.
2. Related Background Art
In recent years, an image input/output apparatus for digitally reading an image and for digitally processing the image and outputting the result has become widespread. Since such an image input/output apparatus handles digital data, there is an advantage that the data can be relatively easily processed and edited. On the other hand, as various kinds of image input/output apparatuses are widespread, a demand for being able to connect two or more kinds of apparatuses and to synthesize different images is increasing more and more.
For instance, as shown in FIG. 2, there is a case where a synthesized copy as shown in (C) is obtained from color images of (A) and (B), or the like. In such a case, for instance, as shown in FIG. 4, the image (A) is input from a scanner S and stored in a memory 1 (M.sub.1) and, thereafter, an image (B) is input from the scanner S and stored in a memory 2 (M.sub.2). Thereafter, the images are properly read out of the memories M.sub.1 and M.sub.2 and synthesized. The resultant synthesized image is stored in a synthesized image memory M.sub.3 and the synthesized image as shown in (C) is output to an output apparatus 0. There is also a case where the memory M.sub.3 also serves as memory M.sub.1 or M.sub.1.
Since the above system has been constructed as mentioned above, in the case where an original of the A4 size is read by the scanner S for every color component at a high density of, e.g., 400 dpi, the memory capacity which is necessary for synthesis may reach 48 megabytes. On the other hand, in the case of reading an original of the A3 size for four colors, memory capacity of 128 megabytes is needed. In the case of a DRAM of 1 megabit capacity, a large number of drams, for instance 1024 (=128.times.8) DRAMs, are needed. Therefore, there are problems that the hardware scale is extremely large and that the system cost rises due to an increase in cost of the memories.
Further, according to such a system, not only are memories of a large capacity needed but also there are problems that it is necessary to access a large amount of image data for synthesis and it is difficult to synthesize the image data at a high speed.
On the other hand, according to the conventional system, since the synthesis is realized by properly switching two first and second inputs mentioned above, the operator needs to previously input to a processing system the location of an image area to be synthesized from the scanner or it is necessary to input image data from the scanner and to send the image data to the processing system. Communicating means or a procedure on the software for this purpose is needed. On the other hand, particularly, in the case where the image data from the scanner is trimmed (partially extracted) and synthesized with the image in the memory, the trimming areas and sizes are variably set by the operators. Thus, it is troublesome to execute the above procedure each time the images are synthesized.